1. Field of the Disclosure
The present disclosure relates to organic light emitting devices and, more particularly, to an organic light emitting display device with improved yield and processing efficiency, which includes an interlayer capable of being separated into a hydrophilic region and a hydrophobic region at a top of a hole injection layer in an organic light emitting device and a plurality of layers including a light emitting layer and which is fabricated without using a shadow mask, as well as a method for manufacturing the same.
2. Discussion of the Related Art
Recently, with progress towards an advanced information society, display applications for visual expression of electric information signals are rapidly growing. In response to such progress, a variety of thin, low weight, low power consumption and excellent performance flat display devices are currently being developed and rapidly replacing existing products such as cathode ray tubes (CRTs).
Examples of such a flat display device (“FDD”) may include a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), an organic light emitting device (OLED), and the like.
Among these, an OLED useful for manufacturing a compact device and embodying a clear picture quality without need for an additional light source such as backlight is considered to be competitive in related applications.
In general, such an OLED requires an organic emitting layer and formation of the organic emitting layer is conducted by deposition using a shadow mask.
A conventional method for fabrication of an OLED will be described in detail by the following description with reference to the accompanying drawings.
FIG. 1 is a perspective view illustrating a general shadow mask and a process for deposition of a light emitting layer using the same.
As illustrated in FIG. 1, a commonly used shadow mask comprises a flat base 1 having at least one slit 2 extended in one direction at a certain width.
A vaporized emission material is exhausted as a gas through the slit 2 and is in turn deposited on a substrate 10 to form a light emitting layer 5.
FIG. 2 depicts a cross-section of the commonly used shadow mask with some problems thereof.
As illustrated in FIG. 2, the shadow mask 1 is positioned below the substrate 10 and the substrate 10 is placed such that the mask 1 is opposite to a face of the substrate on which a light emitting layer 5 is formed. In this case, vaporized gas is fed from a bottom of the mask 1 through slits 2 so as to form the light emitting layer 5.
However, if the shadow mask is used for a process for manufacturing a large-scale organic light emitting display device as shown in FIG. 2, a heavy weight of the shadow mask may cause deflection. Accordingly, the shadow mask has difficulty in repetitive use and may cause failure in forming a pattern on an organic emitting layer. For instance, use of the base 1 has problems in that the base may be bent or deformed, a cleaning agent ingredient may remain after rinsing, damage may occur at a boundary of the slit 2 during formation of the shadow mask 1, and/or alignment error may be encountered. Optionally, particles 1a generated during deposition may cause failure during a following deposition.
In order to solve the above problems, a novel alternative to conventional shadow masks is required. Specifically, there is a strong requirement for development of a new deposition process in order to replace use of a shadow mask in an apparatus for fabrication of a large-scale organic light emitting display device, which causes deflection of the center portion of the shadow mask due to a weight thereof.
A conventional process for fabrication of an organic light emitting display device commonly used in the art entails the following problems.
A process for fabrication of a large-scale organic light emitting display device has difficulties in manufacturing a product caused by a weight of a shadow mask and may cause pattern failure due to deflection of the shadow mask.
With regard to manufacturing of a large-scale organic light emitting display device, a new process for formation of an organic semiconductor layer including a light emitting layer is required.
In addition, for general evaporation deposition using a shadow mask, raw material consumption is high. Therefore, investigation into a process change has been proposed in order to increase raw material utilization efficiency.